As we search for ETIs we ask ourselves, "since any alien intelligence detected will be thousands, if not millions of years beyond us technologically, why do we assume they would use the electromagnetic spectrum for their communications?" This question being on my mind I decided to investigate alternative modes of interstellar communications.

The first question is, do all ETIs use the same senses as we do to "feel" their enviroment? The answer to that is an obvious no. The human lifeform is highly unlikely to be repeated anywhere else in the universe. Other intelligent beings could have some of the same senses as we do. But the star that their home planet orbits dictates, for example, their visual frequency range. Thus, ET might well see only in the infra red or ultra violet frequencies. Sensing sound could also be in either higher or lower frequencies depending on the atmospheric pressure of their planet. The sense of smell again is dictated by the planetary enviroment. Gravity will determine the stature of the beings; the more massive a planet the more "squat" the stature of its inhabitants. A habitable planet with the mass of Jupiter would produce lifeforms, intelligent or otherwise, low to the ground and muscular. Imagine living on a planet with the atmospheric pressure of Venus. Light would be bent and to those looking over a landscape on that planet, the horizon would seem to "fold" in on itself, giving that planet's inhabitants a rather skewed view of the universe.

Mass shapes space and time, so light is bent by stars and other masses. Radio waves will also be bent. A spacefaring intelligence would know this only too well and understand that to communicate over great distances with each other, or with other intelligent beings, a more instant and reliable method than radio is desirable. We here on Earth may soon have to do the same. How might we achieve real time two way communication where even light years of distance wouldn't bother us? We assume if ET is much more advanced than we are, then they must have that problem solved. Until we discover that technology, we may well remain in total ignorance of their presence.

What if other intelligent life forms evolved from insects? Experience with insects on our own planet indicates that they would probably communicate by chemical means. Would we recognize their intelligence when we see it? Perhaps not.

With this problem in mind I considerered the thought experiment where a particle here on Earth which has a left hand spin, and its twin two million light years away which has a right hand spin, still interact instantaneously with each other. If we change the spin in the particle here on Earth, then instantly the other particle two million light years away reverses its spin. This quantum particle entanglement has now been proved by experiment, though admittedly in the laboratory, at more modest distances than two million light years!

With that experiment in mind, I envisioned a therotical particle spin modulator, with transmit and receive capability. First we need a candidate particle that is common throughout the universe, then we build a vacuum chamber with a high electromagnetic field. We then inject the selected particles into the chamber. By switching the magnetic fields North to South we change the spin of the particles in the chamber, and by switching this field we could modulate a "signal" where all twin particles in the universe should instantly change their polarisation opposite to the chambered particles.

If ETIs are using this "instant" communication technology, then we should be able to detect the rapid spin changes in the particles in our own Galaxy. Polarised light is detected as a matter of course by optical Astronomers, and the same is true in the radio spectrum. If we were to find a area in the sky with rapid polarisation changes, then this could well be an indication of artificial manipulation of those particles by an alien civilization.

In a cloud of gas and dust, particles spin left and right randomly. But if ETI is using the polarisation modulation method of communication then we should be able to detect a "hot" spot of spin change in a cloud of gas, where it seems that all the particles polarise at the same time. I assert that we probably couldn't make any sense out of the changes, but leaving aside the influence of nearby Pulsars and like exotic objects, we must at least contemplate that an intelligent communicating civilization may be involved.